CVE-2026-98385
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: sched/cache: Decouple sched_cache_group from mm to fix UAF Currently the sched cache grouping is by mm and the scheduling statistics sched_cache_stat lives in the mm structure. This ties the life cycle of scheduling stats with mm. In account_mm_sched(), the scheduling stats are accessed by task->mm->sc_stat. However, a task may be switching mm on one CPU when another CPU is running account_mm_sched(), and possibly accessing the old mm that was freed. This problem was found when running tests with KASAN by Hyunwoo: https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/ Instead of serializing the mm access by introducing extra acquisition of rq lock in the mm free path, extract sched_cache_stat from mm_struct, rename it as sched_cache_group and manage its life cycle apart from mm_struct with its own ref counting. This allows us in the next patch access sched_cache_group directly from task, and add a refcount on sched_cache_group when a task links to it. This prevents the use after free issue when accessing stale and released old mm and its sched cache stat a task switches to a new mm while account_mm_sched() is done elsewhere. The other benefit of this restructure is in the future, the grouping of tasks to a LLC would have the flexibility to be associated with a user defined grouping, or cgroup, cookie group, numa_group or others instead of just with a single mm address space. Rename sched_cache_stat to sched_cache_group and turn it into a refcounted object allocated from mm_struct. The mm_struct now holds a pointer (sched_cache_grp) to this object instead of embedding it.
View original CVE JSON
{
"id": "CVE-2026-98385",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-12T06:17:00.547",
"lastModified": "2026-10-24T14:16:40.530",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/cache: Decouple sched_cache_group from mm to fix UAF\n\nCurrently the sched cache grouping is by mm and the scheduling statistics\nsched_cache_stat lives in the mm structure. This ties the life cycle\nof scheduling stats with mm.\n\nIn account_mm_sched(), the scheduling stats are accessed by\ntask->mm->sc_stat. However, a task may be switching mm on one CPU when\nanother CPU is running account_mm_sched(), and possibly accessing the\nold mm that was freed. This problem was found when running tests with\nKASAN by Hyunwoo:\n\n https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/\n\nInstead of serializing the mm access by introducing extra acquisition of\nrq lock in the mm free path, extract sched_cache_stat from mm_struct,\nrename it as sched_cache_group and manage its life cycle apart from\nmm_struct with its own ref counting. This allows us in the next patch\naccess sched_cache_group directly from task, and add a refcount\non sched_cache_group when a task links to it. This prevents the use\nafter free issue when accessing stale and released old mm and its\nsched cache stat a task switches to a new mm while account_mm_sched()\nis done elsewhere.\n\nThe other benefit of this restructure is in the future, the grouping of\ntasks to a LLC would have the flexibility to be associated with a user\ndefined grouping, or cgroup, cookie group, numa_group or others instead\nof just with a single mm address space.\n\nRename sched_cache_stat to sched_cache_group and turn it into a refcounted\nobject allocated from mm_struct. The mm_struct now holds a pointer\n(sched_cache_grp) to this object instead of embedding it."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"include/linux/mm_types.h",
"include/linux/sched.h",
"kernel/exit.c",
"kernel/sched/fair.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "df0d98475954d655571979aa061ecb07d7e00392",
"lessThan": "852ecb6bc0bc0106f44f74ba3944524732486025",
"versionType": "git",
"status": "affected"
},
{
"version": "df0d98475954d655571979aa061ecb07d7e00392",
"lessThan": "28f9c0e0a0b94c5d3e1b634db545f6e1f94858c5",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"include/linux/mm_types.h",
"include/linux/sched.h",
"kernel/exit.c",
"kernel/sched/fair.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "7.2",
"status": "affected"
},
{
"version": "0",
"lessThan": "7.2",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.9",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/28f9c0e0a0b94c5d3e1b634db545f6e1f94858c5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/852ecb6bc0bc0106f44f74ba3944524732486025",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}